Clutch mechanism



Nov. 28, 1950 w, B, ENGLER 2,531,771

CLUTCH MECHANISM Filed Dec. 21, 1945 2 Sheets-Sheet l Nov. 28, 1950 u w.B. ENGLER 2,531,771

CLUTCH MECHANISM Filed Dec. 21, 1945 2 Sheets-Sheet 2 hue or PatentedNov. 28, 1950 CLUTCH .MECHAN I SM William B. Engler, Green Springs, OhioApplication December 21, 1945, Serial No. 636,325

Claims.

This invention relates to means for transmitting power from a rotatingprimary or drive shaft, which may constitute the power out-put shaft ofany suitable power unit, to a secondary driven shaft, through a suitabletransmission mechanism involving the use of a V-shaped belt, with meansfor controlling the application and release of power to and from thesecondary shaft through the V-belt, to rotate and stop the secondaryshaft at will.

The device of the present invention is adapted for general applicationwherever power is to be taken from one shaft and applied to anothershaft at regular or irregular intervals; and particularly to the drivingof the rotary blade reel, or the traction wheels, or both, of a powerlawn mower or similar device, wherein the primary shaft is constantlyrotated as a part of or from a suitable mobile source of power, such asa small internal combustion engine or electric motor, and wherein thesecondary shaft is rotated only at times selected by the operator tooperate said cutting reel or said traction wheels, etc.

In the accompanying drawings:

Fig. l is a longitudinal sectional elevation of one form of the deviceconstructed and adapted to operate in accordance with the principles ofthe present invention;

Fig. 2 is an end view;

Fig. 3 is a transverse section taken on the line 3-3, Fig. 1; L

Fig. 4 illustrates a detail of the structure shown in Fig. 1;

Fig. 5 is a view similar to Fig, 1 but showing a modified form ofcontrol unit;

Fig. 6 is an end view of the structure shown in Fig. 5;

Fig. '7 is a transverse section taken on the line I-LFia. 5; and

Fig. 8 is a circumferential flat development of the control cam of Fig.5.

As shown in Figs. 1 and 5, a secondary shaft I is rotatably mounted insuitable fixed bearings 2 and 3. The bearings 2 and 3 are adapted to besecured to any suitable base 4, such, for example, as the frame of alawn mower. I

The shaft I, in the present instance, is shown as being provided with adriving wheel In which is adapted to be driven by a V-belt B from thepower out-put shaft (not shown) of any suitable power unit, such as alight internal combustion engine or electric motor which could bereadily mounted on the base or frame ll.

The shaft I is also provided with a sprocket,

wheel 5, crew suitable equivalent means, for

connecting the shaft I to the traction wheels or blade reel of a lawnmower, for example.

Keyed to the shaft I is a drum-like element 6 which is provided with adisc-like flange I having an outer peripheral marginal area 8 forming abeveled edge on the disc 1. The disc I forms one part of the drivingwheel Ill, which in the present instance, is in the form of a groovedfaced pulley, the second part of which is formed of a disc II having abeveled marginal outer edge 9 flaring oppositely to the marginal edge 8of the disc I and collectively therewith forming a V-shape peripheralgroove I2 in the pulley ID for the reception of a drive belt B ofV-shaped cross; section.

The V-belt B is adapted to apply the power to the shaft I, through thegrooved faced pulley ID for transmission to another shaft (not shown)such as the blade reel shaft of a lawn mower, through the sprocket 5. I,

The disc II is concentric to the disc I and the shaft I, and is securedto a short stud or rod I3 having one end mounted and slidable axially inan axial bore I l formed in one end of the shaft I.

Rotatably mounted for free rotation on and with respect to theperipheral face of the drum 6, adjacent the disc I, is a plain facedidler wheel I5, and a series of loose, freely rotatable shim plates inthe form of plain discs I6. The idler wheel I5 includes a hub I1 and arim rib I8 adapted to bear against one side face of the pulley disc I.The shim discs I6 are interposed be tween the opposite plain flat sidefaceof the idler wheel I5 and the similar fiat plain inner face of thepulley disc I I.

The peripheral face of the idler wheel I5 and the correspondingperipheral edges of the shim discs 16, collectively, constitute theannular base surface of the belt groove [2 in the pulley l0; and thecollective axial thicknesses of the wheel I5 and shims I6 provide theproper width and depth of V-shaped groove I2 in the pulley ID forfrictionally engaging the converging side faces of the V-belt B, by andbetween the flaring marginal surfaces 8 and 9 of the pulley discs I andl I, in a manner which is normal in V-belt transmissions. By adding orsubtracting discs I6, I6, the width of the V-shaped groove I2 can becontrolled for properly engaging the angular sides of a new V-belt B, orof a V-belt whose side faces have worn away to an extent which wouldpermit the smaller face of the belt to engage the base surface of thepulley groove and cause slippage to occur between the pulley I0 and theV- belt B.

The pulley disc II, the shim discs I6, the idler 3 wheel l5, and thepulley disc 1 are drawn axially into firm successive abutting relationto each other by a series of springs I9, I9, which are individuallymounted in recesse 20, 20, formed in the drum 6. The springs l9, l9 aredisposed on and between the circular heads 2i, 2| of a series of bolts22, 22 and the base surfaces of said re- 7' cesses 2B, 20, through whichthe bolts 22, 22 pass and are secured at their opposite ends to thepulley disc I l.

These opposite ends of the bolts 22, 22 are provided with T-shaped heads23, 23 (see Fig. 4),,

which lie between ribs 2d, 24 formed on the outer side face of thepulley disc II to keep said bolts from turning. The bolts 22, 22 may bewithdrawn by pushing said bolts axially against the action of thesprings l9, 19; until the inner surfaces of the heads 23, 23 aredisposed outside the plane of the outer faces of the ribs 2t, 24',whereupon the bolts 22, 2 2, may be turned 90 until the rectangularheadsl23-line up, with corresponding rectangular openings 25, 25.-formedin-the pulley disc H. The bolts 22 are installed and locked inplacebyreversing this course of procedure.

Obviously;,by pulling the stud or pull-rod I 3 outwardly, as indicatedby v the arrow in Fig. 1, thebeveled: marginal area 90f the pulley discll is movedaway from the opposed beveled marginal area 8-ofthe pulleydisc land releases the belt B from lateral frictional contact with saidmarginalareas of said pulley discs, whereupon the. beltBwilldrop freelyonto the base of the belt groove l2 as formed by the peripheral face ofthe-idler wheel [Brand the peripheral edges of the-shim discs It: Havingbeen released by separation or the pulley discs l and H, the idlerwheel, [sand shim discs i6, it are now free to revolve freely onandwithrespect to the drum and support the released belt B, while the-drum Gandshaft [stand-idle.

Asshown in Fig; 1, the pullingv of the rod, l3} to release the belt B;is accomplished by a bellcranlrl'everSi}, one arm 3 f which isbifurcated;

tospa-n the rod; 13; and to engage a collar 32 on the; rod i3;at-opposite sides-respectively thereof. The second arm 33 of thebell-crank'lever is provided: with-a roller fidwhieh is adapted to be.

en a edsuccessively by; caznlobes 35, eachtof which has'its outer endconcaved, asat: 3L6, toreceive and hold the roller--34, and;consequently the-'bell-crank; lever 33, in, a; position whereythe pulleydiscs iand l I are maintained in, spaced; relation, with thebelt Breleasedifrom the pulley H] thereby.

The lobes 35; Siconstituteparts: ofa cam, 37

which isladapted to berotated about the-axis.

of a, pivot pin 3fi'ztogethenwith, and .by a ratchet wheel. 39, to whichthe cam 31'- issecuredl.

The ratchet wheel 39r is operated; intermitten by'a pawljdfl on a lever4|.

bya pawl Mil-which engages the ratchet wheel 39 and: is, carried'byiarfixed frame which also sup? ports the.;pivot pin 38-:for the cam3!- and the ratchet wheeltfi; anda-lso the pivot pin lfii 'of thebell-crank 'leverfiii. 7

As sh'owniin Fig. 5, the; operating stud 1'01 pullrod I3, is connectedby a U-shaped elementuidid havingxone leg or armv Ma'bifurcated-toreceive The lever. 41: is; adaptedito be rocked: about the axis: of. thepivot 4 the pull-rod l3, behind the collar 32 thereon. The second leg ofthe U-shaped element 30a is adapted to be secured to an axially alignedsupplementary pull-rod l3a which is rotatably and slidably mounted in abearing 5| forming part of a bracket 52.

Secured to the pull-rod l3a is a ratchet wheel 39a which is engageablebya pawl 40a carried by a lever Ma, said lever Ma being rotatablymountedon the pull-rod l3a and operable by a pull cord 43a.

On one end face of the bracket 52, surrounding the pull-rod [3a, isformed an annular cam 31a (see Fig. 7). This cam 31a includesdiametrically opposite high spots or lobes 35a, 35a, with concaveholding faces 36a, 36a, and intermediate. low spots 53a, 53a,

Thelhigh spots or lobes 35a, 35a, of the cam 31a are adapted to beengaged simultaneously by cam followers, in the form of rollers 34a,34m, These cam followers are rotatably mountedonjpivot studs 54, 54projecting'radialiy from the hub55 ofthe ratchet wheel 39a.

An anti-back-llash pawl 41m, in theform o f a flat spring, is secured tothe bracket 52, and is engaged by the ratchet wheel39a'.

In, either instance, Fig. 1 or Fig. 5, pulling on the operating cord 43or 473a will rock. the pawl carrying lever A! or fila and. turntherat'chetj wheel 39 or 39a, and their respective cams 3f1 or 31a, tooperatev the pull-rods I 3 and therebysepa ratev the pulley discs 7 andll for releasingthe. beltB. In each instanceapredetermined angu,

, lar movementofthe ratchetwheels or theircam.

ing the-'pulhrodlfigf-rom the bifurcated arm 31:01

am, as the case may, be, the. disc Hm'ay becom pletely-removed toprovide for replacementotzthes belt B or to add or subtract shim discs;ld'without otherwise disturbing any of" thelotheri parts: of themechanism;

I claim:

1; A controlapparatus for a V belt power transmitting mechanismcomprising a pair of axially aligned and" relatively movable pulleymembers, means for relatively-moving saidmem bers toward each other togrip opposite side faces respectively of the V belt, means forrelativelymoving said members apart to release said belt, and meansfreely rotatable intermediate said members to support said-beltwhen soreleased including plurality of discswhfich'may heir-i=- creased a'nddecreasedin number to effect-proper engagement of the pulleymembersWithsaid'belt;

2. A control apparatus; for a- V- belt power" transmittingmechanismcomprising apair of axially aligned and relatively movablepulley members, means for -relatively-=moving said' members toward eachotherto grip opposite side'faces respectively of the V* belt; cam meanforzrelativelymoving said members apartto release "said-' belt, means;freely rotatable intermediate said members to support! said: belt M whenso releasedi:" and spacer means carried-by the: last mentioned meanscomprising spluralityrof discs which :may be increased andsdecreasedaininumb'er: at wiltlto effect proper engagement of the belt by saidpulley members.

3. A control apparatus for a V belt power transmitting mechanismcomprising a pair of axially aligned and relatively movable pulleymembers, a drum forming part of one of said members, spring meansmounted in said drum and connected to the other of said member to effectgripping or" opposite side faces respectively of a V belt by and betweensaid members, means for separating said members to release said belt,and means rotatable on said drum intermediate said members forsupporting the belt when released.

4. Control apparatus as claimed in claim 3 wherein spacer means isprovided intermediate said pulley members to eiTect proper engagement ofthe belt by said pulley members.

5. Control apparatus as claimed in claim 3 wherein the means rotatableon the drum for sup- 20 8 porting the belt when released includes aplurality of discs which may be increased and decreased in number toeffect proper engagement of the belt by said pulley members.

WILLIAM B. ENGLER.

CITED The following references are of record in the file of this patent:

UNITED STITES PATENTS Number Name Date 1,740,087 Hall Dec. 17, 19292,165,431 Wellman July 11, 1939 FOREIGN PATENTS Number Country Date19,697 Great Britain Sept. 19, 1908 3,710 Great Britain 1909 104,355Australia July 7, 1938

